Route a napplet-originated theme.* envelope (e.g. theme.get) into
the runtime.
The source napplet's windowId
The NIP-5D NappletMessage envelope
Push a shell-initiated theme-domain envelope (e.g. theme.changed)
into a napplet iframe.
No-op when the originRegistry cannot resolve the windowId (unknown or unregistered napplet). Never throws.
The target napplet's windowId
The NIP-5D NappletMessage envelope to deliver
Per-domain proxy for
theme.*envelopes.Shape:
dispatchroutes napplet→shell requests into the runtime;emitpushes shell→napplet envelopes through the iframe's Window.